1. Field of the Invention
The invention relates to a plug connector for connecting to a complementarily formed counter plug connector, in particular for high current or high voltage applications. The plug connector has an inner conductor for conducting a high current and an outer conductor that surrounds the inner conductor. The outer conductor serves to shield the electromagnetic fields which it surrounds. The outer conductor has, for the purposes of shield transfer, an outer contact element on a front side of the plug connector which, on connection, faces a front side of the counter plug connector.
2. Description of Related Art
Plug connectors are used generally for the detachable connection of electrical cables in order, when connected, to permit the transmission of current and/or electrical signals. A first plug connector in the form of a socket part is thereby plugged together with a second plug connector in the form of a plug part to form a plug connection.
High current plug connectors are used to transmit high electric currents, for example with amperage of more than 100 A, e.g., 200 A to 400 A, and are for example used in motor vehicles with electric or hybrid drives. The inner conductor of the second plug connector, which is designed as a plug part, can thereby have a contact blade or a contact pin projecting in an insertion direction, which is inserted into a receiving recess of the first plug connector, which is designed as a socket part, in order to establish an electrical contact between the first plug connector and the second plug connector. An inner contact element of the inner conductor of the socket part is located in the receiving recess.
It is thereby important that the space through which the inner conductor passes is shielded as completely as possible from the outside in order to protect the environment against the radiation of electromagnetic fields, and to keep electromagnetic fields away from the interior of the outer conductor. This shielding is provided through the outer conductor which is formed of an electrically conductive material, which generally surrounds the inner conductor in a tubular or similar arrangement. In the vicinity of a plug connection it is important to ensure a continuous shielding through a shield transfer between the outer conductor of the plug connector (socket part) and the outer conductor of the counter plug connector (plug part), so that no electromagnetic fields can escape outwards.
In high current plug connectors the requirement therefore exists that, while requiring little construction space, a reliable electrical contact is established between the inner conductors and the outer conductors of the plug connector and counter plug connector, whereby this contact is intended to guarantee that even under a high loading with mechanical vibrations high electrical currents are shielded and transmitted in a functionally reliable manner without the contact points being subjected to wear.
In conventional plug connectors, the shield transfer is effected through spring-mounted contact elements projecting in the insertion direction which, when the connector is plugged together, come into contact with a peripheral contact surface of the counter plug connector and slide along this in the insertion direction until the inner contact elements fully engage in one another.
However, it has transpired that such a shield transfer often leads to inadequate shielding, and that the contact points are also subjected to a high level of wear with relatively high contact resistance.